Spectroscopy, Relaxation, and Transport of Molecular Excitons in Noisy and Disordered Environments

Spectroscopy, Relaxation, and Transport of Molecular Excitons in Noisy and Disordered Environments PDF Author: Chern Chuang
Publisher:
ISBN:
Category :
Languages : en
Pages : 150

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Book Description
In this thesis contribution we theoretically investigate the spectroscopy, relaxation, and transport properties of Frenkel excitons in molecular aggregates, with extensive comparison to or prediction of experimental observables. Particular emphasis is devoted to the effects of thermal noise, static disorder, and system dimensionality. Our key contributions are summarized as the following. We study the spectroscopic signatures of excitonic molecular aggregates of dimensionality larger than unity as functions of temperature and disorder strength. These findings are applied to the determination of essential system characteristics and quantitatively explain the spectroscopic traits seen in experiments where either the temperature or disorder strength is altered. A classification scheme generalized from Kasha's seminal work on J- and H-aggregates is proposed that is compatible with experimental observations previously unexplained. We recognize the importance of long-wavelength approximations in understanding the density of states in two-dimensional excitonic aggregates. And for tubular aggregates this leads to a simple expression for the energy gap between the parallel- and the perpendicular-polarized peaks useful in inferring key system parameters. This long-wavelength approach is then extended to the analysis of 2D excitonic molecular aggregates in general. A universal scaling relation concerning the steady-state diffusive transport of excitons in molecular tubes is predicted and analyzed, where the key order parameter is identified as the ratio between the localization length of the exciton wavefunctions and the tube circumference. A unified theoretical framework is proposed to explain the relaxation of hot excitons generated in emissive conjugated polymers across three orders of magnitude in timescale, with quantitative agreements with experiments.

Spectroscopy, Relaxation, and Transport of Molecular Excitons in Noisy and Disordered Environments

Spectroscopy, Relaxation, and Transport of Molecular Excitons in Noisy and Disordered Environments PDF Author: Chern Chuang
Publisher:
ISBN:
Category :
Languages : en
Pages : 150

Get Book Here

Book Description
In this thesis contribution we theoretically investigate the spectroscopy, relaxation, and transport properties of Frenkel excitons in molecular aggregates, with extensive comparison to or prediction of experimental observables. Particular emphasis is devoted to the effects of thermal noise, static disorder, and system dimensionality. Our key contributions are summarized as the following. We study the spectroscopic signatures of excitonic molecular aggregates of dimensionality larger than unity as functions of temperature and disorder strength. These findings are applied to the determination of essential system characteristics and quantitatively explain the spectroscopic traits seen in experiments where either the temperature or disorder strength is altered. A classification scheme generalized from Kasha's seminal work on J- and H-aggregates is proposed that is compatible with experimental observations previously unexplained. We recognize the importance of long-wavelength approximations in understanding the density of states in two-dimensional excitonic aggregates. And for tubular aggregates this leads to a simple expression for the energy gap between the parallel- and the perpendicular-polarized peaks useful in inferring key system parameters. This long-wavelength approach is then extended to the analysis of 2D excitonic molecular aggregates in general. A universal scaling relation concerning the steady-state diffusive transport of excitons in molecular tubes is predicted and analyzed, where the key order parameter is identified as the ratio between the localization length of the exciton wavefunctions and the tube circumference. A unified theoretical framework is proposed to explain the relaxation of hot excitons generated in emissive conjugated polymers across three orders of magnitude in timescale, with quantitative agreements with experiments.

Light Harvesting in Photosynthesis

Light Harvesting in Photosynthesis PDF Author: Roberta Croce
Publisher: CRC Press
ISBN: 1351242873
Category : Science
Languages : en
Pages : 793

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Book Description
This landmark collective work introduces the physical, chemical, and biological principles underlying photosynthesis: light absorption, excitation energy transfer, and charge separation. It begins with an introduction to properties of various pigments, and the pigment proteins in plant, algae, and bacterial systems. It addresses the underlying physics of light harvesting and key spectroscopic methods, including data analysis. It discusses assembly of the natural system, its energy transfer properties, and regulatory mechanisms. It also addresses light-harvesting in artificial systems and the impact of photosynthesis on our environment. The chapter authors are amongst the field’s world recognized experts. Chapters are divided into five main parts, the first focused on pigments, their properties and biosynthesis, and the second section looking at photosynthetic proteins, including light harvesting in higher plants, algae, cyanobacteria, and green bacteria. The third part turns to energy transfer and electron transport, discussing modeling approaches, quantum aspects, photoinduced electron transfer, and redox potential modulation, followed by a section on experimental spectroscopy in light harvesting research. The concluding final section includes chapters on artificial photosynthesis, with topics such as use of cyanobacteria and algae for sustainable energy production. Robert Croce is Head of the Biophysics Group and full professor in biophysics of photosynthesis/energy at Vrije Universiteit, Amsterdam. Rienk van Grondelle is full professor at Vrije Universiteit, Amsterdam. Herbert van Amerongen is full professor of biophysics in the Department of Agrotechnology and Food Sciences at Wageningen University, where he is also director of the MicroSpectroscopy Research Facility. Ivo van Stokkum is associate professor in the Department of Physics and Astronomy, Faculty of Sciences, at Vrije Universiteit, Amsterdam.

Physics Briefs

Physics Briefs PDF Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1108

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Book Description


Quantum Effects in Biology

Quantum Effects in Biology PDF Author: Masoud Mohseni
Publisher: Cambridge University Press
ISBN: 1107010802
Category : Science
Languages : en
Pages : 421

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Book Description
Explores the role of quantum mechanics in biology for advanced undergraduate and graduate students in physics, biology and chemistry.

Photosynthetic Excitons

Photosynthetic Excitons PDF Author: Herbert van Amerongen
Publisher: World Scientific
ISBN: 9789810232801
Category : Science
Languages : en
Pages : 612

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Book Description
Excitons are considered as the basic concept used by describing the spectral properties of photosynthetic pigment-protein complexes and excitation dynamics in photosynthetic light-harvesting antenna and reaction centers. Following the recently obtained structures of a variety of photosynthetic pigment-protein complexes from plants and bacteria our interest in understanding the relation between structure, function and spectroscopy has strongly increased. These data demonstrate a short interpigment distance (of the order of 1 nm or even smaller) and/or a highly symmetric (ring-like) arrangement of pigment molecules in peripheral light-harvesting complexes of photosynthetic bacteria. Books which were devoted to the exciton problem so far mainly considered the spectral properties of molecular crystals. However, the small size of these pigment aggregates in the pigment-protein complexes as well as the role of the protein, which is responsible for the structural arrangement of the complex, clearly will have a dramatic influence on the pigment spectra and exciton dynamics. All these aspects of the problem are considered in this book. Exciton theory is mainly considered for small molecular aggregates (dimers, ring-like structures etc.). Together with the theoretical description of the classical conceptual approach, which mainly deals with polarization properties of the absorption and fluorescence spectra, the nonlinear femtosecond spectroscopy which is widely used for investigations now is also discussed. A large part of the book demonstrates the excitonic effects in a multitude of photosynthetic pigment-protein complexes and how we can understand these properties on the basis of the exciton concept.

Current Programs

Current Programs PDF Author:
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 426

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Book Description


Ultrafast Spectroscopy

Ultrafast Spectroscopy PDF Author: Joel Yuen-Zhou
Publisher: Iop Expanding Physics
ISBN: 9780750310635
Category : Science
Languages : en
Pages : 0

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Book Description
The goal of this book is to provide a simple and conceptually intuitive introduction to nonlinear spectroscopy via the formalism of quantum processes and wavepacket dynamics.

Single Molecule Spectroscopy

Single Molecule Spectroscopy PDF Author: R. Rigler
Publisher: Springer Science & Business Media
ISBN: 3642565441
Category : Science
Languages : en
Pages : 375

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Book Description
The topics range from single molecule experiments in quantum optics and solid-state physics to analogous investigations in physical chemistry and biophysics.

Carbon Nanomaterials for Biomedical Applications

Carbon Nanomaterials for Biomedical Applications PDF Author: Mei Zhang
Publisher: Springer
ISBN: 3319228617
Category : Technology & Engineering
Languages : en
Pages : 576

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Book Description
This book covers a wide range of topics relating to carbon nanomaterials, from synthesis and functionalization to applications in advanced biomedical devices and systems. As they possess unique and attractive chemical, physical, optical, and even magnetic properties for various applications, considerable effort has been made to employ carbon nanomaterials (e.g., fullerenes, carbon nanotubes, graphene, nanodiamond) as new materials for the development of novel biomedical tools, such as diagnostic sensors, imaging agents, and drug/gene delivery systems for both diagnostics and clinical treatment. Tremendous progress has been made and the scattered literature continues to grow rapidly. With chapters by world-renowned experts providing an overview of the state of the science as well as an understanding of the challenges that lie ahead, Carbon Nanomaterials for Biomedical Applications is essential reading not only for experienced scientists and engineers in biomedical and nanomaterials areas, but also for graduate students and advanced undergraduates in materials science and engineering, chemistry, and biology.

Polariton Chemistry

Polariton Chemistry PDF Author: Joel Yuen-Zhou
Publisher:
ISBN: 9781119783299
Category :
Languages : en
Pages : 452

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Book Description
This book provides a pedagogical introduction to the emerging field of Polariton Chemistry, where optical cavities are utilized to control the physicochemical properties and dynamics of molecular systems. Given the early stages of this interdisciplinary research area, it is important to provide a common language and starting point for interested researchers across Chemistry, Physics, and Engineering This edited compendium fills a void given that there is currently no analogue in the current literature. Topics covered include Single-Molecule Strong Light-Matter Coupling; Collective Strong Light-Matter Coupling; and Ultrastrong Light-Matter Coupling